Transcript Bond - My CCSD

Bellwork: Monday 3/19/2012


Why do elements in the same
families (groups) on the periodic
table have the same properties?
A. They have the same atomic
number and mass number.
B. They have the same number of
electrons.
C. They have the same number of
valence electrons.
D. They have very similar mass
and atomic numbers.
Which element is contained in all of
the following chemical compounds?
CO2, NaHCO3, C6H12O6, and C4H10

Which of the following pairs share
similar properties?
A. Oxygen (O) & Iodine (I)
B. Fluorine (F) & Neon (Ne)
C. Bromine (Br) & Iodine (I)
D. Helium (He) & Hydrogen (H)

Which group of elements would be
expected to have very similar
properties?
A. Nitrogen, oxygen, fluorine
B. Oxygen, sulfur, selenium
C. Sodium, magnesium, potassium
D. Neon, sodium, potassium
Adopt-An-Element
Adopt-A-Molecule Project
3D Model
DUE Thursday 3/22/2012
 Element- Bohr model (pro, neu,
ele, shells), must hang
 Molecule- poster, model, mobile,
etc.; must show correct number of
each atom, and structure (NOT
Bohr Model)
Review of Chemistry- Packet 11, Page 1
Individually and silently, you have 8 minutes to finish.
Use your notes in Packet 10 if necessary.
1.
2.
3.
4.
5.
6.
7.
8.
The smallest particle of matter that retains its chemical properties is
atom
called an _______________.
protons
The subatomic particles in an atom are called ___________,
neutrons
electrons
____________,
and ____________.
protons and ____________.
electrons
Neutral atoms have equal numbers of __________
periods
The horizontal rows in a periodic table are called _____________.
groups
The vertical columns on a periodic table are called ______________.
1 & 17 are the most reactive. These groups are
Elements in Groups ______
Alkali Metals & Halogens
called ____________________________.
18 are the most non-reactive. This group is
Elements in Group ___
Noble Gases
called ______________________.
Each group/family of the periodic table has elements with chemical
characteristics that are (circle one):
exactly the same / similar / different / exactly opposite
9.
If an atom had the same properties as fluorine, it would probably be
Group 17, Halogens
located in _____________________.
When atoms bond, only electrons in the outer (valence)
shell are involved. Valence electrons are shown with
Lewis Dot Diagrams. Below, draw the Lewis diagrams for
the first 20 elements.
1
2
13
14
15
16
17
18
Bond: (def.) A bond is the
combining of atoms from various
elements to form a new substance
6.2- TSW EXPLAIN THAT
COMPOUNDS FORM
WHEN TWO OR MORE
DIFFERENT KINDS OF
ATOMS BOND.
When atoms bond together, they
combine to form a molecule or a compound
 6.4- TSW COMPARE AND CONTRAST
MOLECULES AND COMPOUNDS.

Molecule – a combination of 2 or
more atoms that are bonded together
 Ex: H2, O2, O3, N2

Compound – a
molecule that contains
at least 2 different
elements
 Ex: H2O, C6H12O6, CH4
A chemical bond…
Is the strongest bond that can hold atoms together
 Is determined by the atomic structure of each atom
 Occurs in the valence electron shell
 Three types of chemical bonds:

Covalent
Ionic
Metallic
Covalent Bonds
 The
“nice” bonds
 Covalent bonds form
when atoms share their
electrons to become
more stable
*Occurs between
non-metals and
non-metals
Properties of Covalent Bonds
 Weak
bonds – can be
easily separated
They
 Low melting and boiling
share!
points (Often found in
liquids and gases)
 Poor conductors
 Examples:
They
 Water: H2O
 Oxygen gas: O2
 Ammonia: NH4
 Methane gas: CH4
share
too! 
Methane: CH4

21 times more powerful
greenhouse gas than CO2
 Responsible for nearly as much
global warming as all other
non-CO2 greenhouse gases put
together

Produced when organic
matter decays
 Naturally by farm animals
(like cows)
Metallic Bonds
*Occur between
atoms of two or
more metals
The “hippie” bonds 
 Metallic bonds occur when
atoms (metal) share their
“free” valence electrons with
other atoms (metal) so that
every atom will be stable

Properties of Metallic Bonds
 Loosely
held electrons move
freely from atom to atom
 Malleable and ductile
 Good conductors
 Ex: Copper, Gold,
Silver, Aluminum
Bellwork: Thursday 3/22/12
 Anions
have more/less electrons and cations
have more/less electrons. (circle the answer)
 Determine
if the following elements are a
metal or a non-metal:
H
Non - metal
 Fe
Metal
 Li
Metal
 Ca
Metal
 Te
Metal
 Cl
Non - metal
F
Non - metal
 Ar
Non - metal
U
Metal
 Cu
Metal
Ionic Bonds
*Ionic bonds form
between metals
and non-metals
The “greedy” or
“generous” bonds
 Form when one atom
takes electrons from
another atom so that
both atoms can become
stable
 *Results in ions: cations
(+) and anions (-) that
attract to one another

Properties of Ionic Bonds
 Strong
bonds between atoms
 Crystalline structures
 Solid state of matter
 High melting point and
boiling points
 Good conductors of electricity
 Ex: NaCl
The Nature of
the Ionic Bond
Held together by
strong attractions
between the
positive and
negative charges
 Remember:

 The cation is the
positively (+)
charged ion
 The anion is the
negatively (-)
charged ion

The greater the
charge, the greater
the attraction
Example of an Ionic
Bond: NaCl

Table salt (NaCl) is a compound formed when sodium
(Na) and chlorine (Cl) combine through ionic bonds
• Na loses its electron, becomes a
positively charged ion (cation) called Na+
• Cl gains an electron, becomes a
negatively charged ion (anion) called Cl• Becomes two attracting ions, Na+Cl-
Packet 11, Page 3Use your Periodic Table to practice
classifying these compounds as
having covalent or ionic bonds…

CaCl3
Ionic bond (Ca – metal, Cl – non-metal)

H2 O
Covalent bond (H – non-metal, O – non-metal)

LiBr
Ionic bond (Li – metal, Br – non-metal)

NaF
Ionic bond (Na – metal, F – non-metal)

MgO
Ionic bond (Mg – metal, O – non-metal)

CH4
Covalent bond (C – non-metal, H – non-metal)
Counting Atoms in a
Compound
 Compounds
are made up of
different types of elements, with
varying numbers of each atom
 The
way to represent this quickly
and efficiently is by using a
chemical formula
 A chemical formula tells:
 which elements are in the compound
 the exact number of each type of
atom
Chemical Formula Introduction

Using a car as an analogy for a molecule: You
have a Porsche 911 Turbo.
How many tires (T), doors (D), and engines
(E) does the car have?
 4 tires, 2 doors, and 1 engine

Now, write this as a molecule: T4D2E
 Note: If there is no number, then there's one of those
things there, like the ‘E’ above. If there weren't any,
you wouldn't write the symbol at all.

Does the car remain the same if you change
the number of tires, doors, or engines?
 Of course not!

How can you change the number of cars from
1 to 3?
 By doing the following: 3(T4D2E)
 The “3” in this formula is called the coefficient.

What would be the formula for the tractor?
 T4E
C6H12O6
The atomic symbol
depicts each atom in
the molecule
C6 = 6 atoms of carbon

H12 = 12 atoms of hydrogen
Subscript- The little numbers in chemical
formulas that tell you how many of that
atom are in the molecule


The subscripted number
represents the number
of each atom
“Sub" means “under/below”
Coefficient- The big number in front of a
chemical formula that tells you how many
molecules there are
O6 = 6 atoms of oxygen
Be(OH)2
The parentheses
show a smaller
molecule within the
larger compound
Be – 1 atom of
beryllium in the
molecule
Beryllium hydroxide
This number outside the parenthesis
(subscript) represents the number of
molecules within the compound
(OH)2 – 2 molecules of OH
•2 atoms of oxygen
•2 atoms of hydrogen
3CO2
The coefficient tells
you the number of
molecules of the
compound, and
applies to every
element in the
molecule.
3 molecules of CO2
•3 atoms of Carbon
•6 atoms of Oxygen
Subscripts vs. Coefficients

The subscripts
tell you how
many atoms of
a particular
element are in a
compound.
1)
(1) Calcium, (2) Fluorine
CaF2 _____________________________________________
2)
(1) Beryllium, (2) Oxygen, (2) Hydrogen
Be(OH)2 __________________________________________
3)
(3) Nitrogen, (6) Oxygen
3NO2 _____________________________________________
4)
(2) Aluminum, (3) Sulfur, (12) Oxygen
Al2(SO4)3 _________________________________________
5)
(2) Nitrogen, (4) Hydrogen, (3) Oxygen
NH4NO3 __________________________________________
6)
(2) Sulfur, (2) Fluorine
S2F2 _____________________________________________
7)
(4) Sodium, (2) Carbon, (6) Oxygen
2Na2CO3 __________________________________________
8)
(1) Carbon, (4) Hydrogen
CH4 ______________________________________________
Bellwork: Friday 3/23/2012
metals and non-metals
Ionic bonds form between _______
____________.
2. Covalent bonds form between ____________
non-metals and
non-metals
____________.
metals
metals and _________.
3. Metallic bonds form between _________
1.
covalent bond.
S2F2 would form a(n) ___________
ionic
5. CaF2 would form a(n) ___________
bond.
6. NO2 would form a(n) ___________
covalent bond.
4.
True/False. Oxygen gas, O2 , is a compound. Why?
 FALSE! Compounds are two or more DIFFERENT atoms
bonded together. O2 is a diatomic molecule.
7.
PRACTICE!!
Count the atoms of each element in the following:
1.
CuSO4
 (1) Copper, (1) Sulfur, (4) Oxygen
2.
3KMnO4
 (3) Potassium, (3) Manganese, (12) Oxygen
3.
Ca(ClO4)2
 (1) Calcium, (2) Chlorine, (8) Oxygen
4.
2(NH4)3PO4
 (6) Nitrogen, (24) Hydrogen, (2) Phosphorus,
(8) Oxygen
Drawing Covalent Chemical Bond
“Skeletons” from Formulas- Page 3
What atoms are in these molecules? How many of each? Draw it!

O2
 (2) Oxygen

H2
O-O
H-H
 (2) Hydrogen

O3
 (3) Oxygen

Cl2
 (2) Chlorine

CO2
O-O-O
Cl-Cl
O-C-O
 (1) Carbon, (2) Oxygen

3CO2
 (3) Carbon, (6) Oxygen
NOT: Cl-l
O-C-O
O-C-O
O-C-O